/Engine/Plugins/Experimental/Web/WebAPI/Source/WebAPIEditor/Public/WebAPIEditorSubsystem.h
After a WebAPI Definition is being (re)imported.
typedef TMulticastDelegate_ThreeParams< void, bool, [FName](API\Runtime\Core\UObject\FName), [UWebAPIDefinition](API\Plugins\WebAPIEditor\UWebAPIDefinition) * > FOnWebAPIDefinitionPostImport